1. Field of the Invention
The invention relates to a display device comprising a display tube having a rectangular display window with a short axis and a long axis and an inside surface on which a display screen is provided, electron gun means for generating at least one electron beam and which is arranged opposite the display screen, and a deflection system located between the electron gun means and the display screen. Such display devices are used in, inter alia, television receivers and computer monitors.
2. Description of the Related Art
A problem with this type of display devices is so-called raster distortion. Due to raster distortion, a straight line is reproduced as a curved line on the display screen. In future HDTV systems this problem will become more serious. Such systems employ higher line and field scanning frequencies than the conventional systems and generally have a larger display screen. Raster distortion is more conspicuous in relatively large display screens, and is difficult to correct at comparatively high frequencies. In general, correcting raster distortion becomes more difficult according as the flatness of the display window increases.